Due to space limitations and the cost of operating conveying lines, the efficiency of a conveyor system is a substantial consideration. Thus, buffer systems are often required to store articles on a conveyor system to maximize throughput efficiency.
Two lane conveying systems are desirable because they can effectively double the articles manufactured within a given time period. However, a major concern of two rail conveyor systems is the space required for such systems, particularly when a single lane conveyor, or a portion thereof, is being replaced by a two rail conveyor system. For instance, for the present invention it is desirable to have a space of only approximately one to two inches between the two lanes.
U.S. Pat. Nos. 4,964,498 to Klingl and 5,253,743 to Haas, Sr. et al. both disclose conveyors having side by side vertical storage buffers. U.S. Pat. No. 5,176,242 to Wegscheider discloses two buffer magazines 12, 32 positioned one after the other. The Klingl, Haas and Wegscheider conveyor systems, however, use the side by side buffers to efficiently convey articles in a single lane, not two lanes.
U.S. Pat. No. 4,561,819 to Wiernicki discloses a conveyor magazine having the shape of a vertical stack for storing printed circuit boards (PCBs). The Wiernicki magazine, however, does not include conveyors on each level of the magazine to load and withdraw articles. The Wiernicki magazine relies on rollers 80 external to the magazine to load and withdraw articles. Relying on an external drive system for a magazine can be disadvantageous if the magazine is being retrofitted to an existing system without an appropriate drive system.
None of the above patents discloses a storage buffer for use with a conveyor system having two side-by-side driven lanes.
What is desired, therefore, is a two magazine multi-level storage buffer that can convey articles on each storage level and be used with a conveyor system having two side-by-side driven lanes, and that adheres to strict width limitations between the lanes.